Some New Circuits for High-Power Traveling-Wave Tubes

A discussion of new types of slow-wave structures, in which the coupling between sections is obtained largely by negative mutual inductance, is given in this paper. Since this type of coupling can be used to give "fundamental" amplifier operation with relatively high impedance, the devices are somewhat unusual in the field of high-power traveling-wave tubes. Several structures which make use of this type of coupling are examined in a qualitative manner, and the results of "cold tests" on each model are given. In particular, one device, the so-called "clover-leaf" structure, is investigated in some detail. Curves of impedance, C, and gain at megawatt power levels are included. Some discussion of the practical problems involved in the design of an amplifier using this circuit is presented to serve as a guide for those interested in the construction of high-power traveling-wave tubes.